Can't read most numbers on an old steel 72 tank

[PBcatfish]

I've always liked the old 2250 psi steel 72's. I just came across one a few days ago. It has the modern style neck threads. The J valve still works. The inside of the tank is still shiny. I'd like to get it hydro'd & put back into service.


Unfortunately, the only numbers I can read on the tank head are the old hydro test stamps. One is from 1977 & the other is from the '80's. The paint is faded from yellow (under the boot) to almost a pale white. The US Divers logo sticker on the tank makes me think that the paint is likely original, but if that is true, it is so thick that it covered up all the numbers that were stamped into the tank other than the Hydro dates. The 1977 date is painted over, but easily readable. The later date is stamped through the paint. There is no rust at the newer hydro date, so I am thinking that maybe this thing never got used after the second hydro.

Has anybody here in the vintage zone seen this kind of paint-over on older tanks?

 

[captain]

Sounds more like vinyl coated than paint. They were hard to read.

 

[Tracy]

All of the old vinyl coated 72s were hard to read. If you shine your flashlight at the right angle, you can usually make out the markings. Next step would be a paper and pencil scribed over them.

 

[PBcatfish]

I think that you two gentlemen hit the nail on the head.

Upon closer examination, the 1977 hydro looks to be melted into the coating, not stamped into the tank then painted over.

Where the 1982 hydro is stamped, small flakes of the coating came off & measures .01" thick. That's a lot of thickness for paint.

When I shine a light sideways above the 1977 hydro, I can just make out the numbers 70. I can't feel them, I can just barely see them.

That's all I can find that I can make out. The steel under the coating looks like it might be galvanized, so that would be a plus for me.

I guess that maybe I'll take an old putty knife, heat it up in boiling water & see if I can melt/score some lines into the coating, then peel it off?????

On the coated tanks, were the rest of the numbers stamped into the steel? Or were they just in the coating?

 

[rjack321]

The best way to take off the vinyl is with a heat gun and a putty knife. Assuming its galvanized underneath this is worth the effort. If it's bare steel underneath then you can repaint it with a cold galvanizing paint but it ends up being a ton of effort for a marginal tank in the end. Either way an honest VIP requires that thick vinyl coating to come off to see if there are pits or corrosion in the base metal.

All the relevant numbers are stamped into the actual steel.

ps edit: the orange based paint strippers also work on the vinyl coatings

 

[PBcatfish]

A closer look with a UV light at an angle shows "US Divers" around the neck & a few random numbers here & there. All look to be about 1/2" high, which is larger than I expected.

That coating is pretty tough. I guess that they had good plastics back in the 70's.

 

[Tracy]

A closer look with a UV light at an angle shows "US Divers" around the neck & a few random numbers here & there. All look to be about 1/2" high, which is larger than I expected.

That coating is pretty tough. I guess that they had good plastics back in the 70's.

They didn't have to worry about toxic fumes, they used good stuff.

No reason to remove the outer coatings. They are tough and do a good job of protecting the tanks.
They don't need removed for a visual inspection, any pitting under the coating is very apparent both inside and outside the tank.
If it is flat and smooth, there isn't moisture or damage underneath.

 

[PBcatfish]

i can't read the serial number. I assume that is going to be an issue

 

[Tracy]

i can't read the serial number. I assume that is going to be an issue

It is only an issue if the hydro guy can't read it. They will probably make it out. It has been hydroed before.

 

[captain]

If it's galvanize under the vinyl you got lucky, all weren't. I would only remove it if it interferes with n it hydroed.